Compressor unloading mechanism



Oct. 19, 1943. P, DISERENS COMPRESSOR UNLOADI'NG MECHANISM Pau! Ber/9175.

- Filed Jan. 5, 1942 ATTORNEY Oct. 19, 1943. P. DlsERENs .2,332,372

COMPRESSOR UNLOADING MECHANISM Filed Jan. 3, 1942 2 sheets-sheet 2 a a'. l l o Patented Oct. 19, 1943 COMPRESSOR UNLOADING MECHANISM Paul Diserens, Summit, N. J., assg'nor to Worthl ington Pump and Machinery Corporation, Harrison, N. J., a corporation of Delaware Application January 3, 1942, Serial No. 425,522

7 Claims.

- This invention relates to compressors and more lparticularly to compressor loading and unloading means. V

An object of the invention is to provide an unloading mechanism of the start and stop type for compressors which will unload the compressor upon its stopping and maintain it in unloaded condition after'it has started until it has picked up speed, thereby minimizing the load on the,

prime mover of the compressor during starting periods of operation.

Another object of the invention is the provsion of a stop and start unloader for compressors which utilizes'a combination of centrifugal' force and hydraulic clutch action for operating a valve to control the loading and unloading of the compressor.

A further object of the present invention is to which mechanical friction in the unloading valve operating means is eliminated.

More specifically, the present invention coinvprehends an unloading mechanism in which a hydraulic clutch of the Foettingentype is employed as a coupling medium between the compressor driving shaft and the unloading mechanism whereby the unloading mechanism will not be operated to load the compressor until the compressor has reached a speed, upon starting' Ainvention vconsists of various features of construction and combination of parts, which will beA rst described in connection with the accompanying drawings, showing a compressor unloading mechanism of the preferred form embodying the invention', and the features forming the inventionV will be specically pointed out in the (ZlLlZILS.r 1

, In thedrawings Figurel `is a vertical section through a compressor equipped with the improved `unloading mechanism, f lFiguresZ 4V is an enlarged longitudinal' section throughv thezunloading mechanism.

-Figure isma vertical section taken on `the line 3- 3 ,of Figure 2.

I Figure, 4 is a vertical section taken on the line 4-4 of Figure 2.

Figure 5is a vertical section taken on the line 5-5of Figure 2.

Referring more particularly to the drawings, I

indicates a compressor of any approved type em- A bodying a compressing piston 2, operated by the 'driving shaft 3. The driving shaft 3 is driven `provide a compressor unloading mechanism in from any suitable 'type of prime mover (not shown), and the iluid compressed by the comypressor is discharged through the discharge from the compression space 4 through the connection 4'. For'the purpose of unloading the compressor, upon starting, to relieve the prime mover of starting stresses, a pipe 5 is connected to the dischargeA line 4 between the compressor and the check valve B, and this unloading'pipe 5 opens into a valve housing 1, which latter is provided with ports 8 opening to atmosphere. The ports 8 are controlled by a valve piston 9, mounted for reciprocating movement within the housing 1. When the valve 9 is seated against the valve seat I0, the ports 8 are closed and communication between the vcompression space 4 of the compressor and Vthe atmospherathrough the pipe 5 andl discharge line 4,'is shut olf, at which time the compressor will operate'in loaded condition.

When the valve 9 is in its lowered position, as.

shown in Figure 2 of the drawings, the ports 8 are open and consequently the discharge line 4 and compression space 4 will be open to atmosphere, permittingoperation of the compressor in an unloaded condition.

The valve piston 9 has a valve stem II connected thereto which projects into the housing I2 containingthe mechanism for operating the valve 9.l The valve ystern II hasA a head I4 on its inner or lower end, which head I4 is held in engagement with the peripheral surface of a cam I5 by means of a spring I6, The spring I6 is engaged at its end opposite to the head I4 b y a spring tensioning nut I1, and the tension of `the spring may be regulated by adjustment of said vnut I1.

The cano I5 is rotatably mounted upon a shaft extension Iconnected to the driving shaft 3 of thecompressor in any suitable manner. A sleeve I9 ifleither formed integrally with'or xedly connected toY the cam I5, and has the driven impeller structure 20 ,of the hydraulic coupling structure 2l mounted thereon. The hydraulic coupling or clutch structure 2| is of the simple Foettinger type, comprising al drivingv element or propeller 22, direct connected to the driving shaft 3 ofthe compressor for rotation therewith, and the driven element 20, in conjunction with the housing 26. The vanes 24 of the driving element 22 and the vanes 25 of the driven element 20 are enclosed Within`said coupling housstarting, may be varied; or,'the .oper

ing 26, which latter is open, by means of ports 2l. to the interior of the housing I2. vThe housing I2 is open to the lubricating system of the compressor through a suitable port or `ports v28, so that a part of the oil from the lubricating system of the compressor will flow into the interior of the housing I2, at least partially filling it, and thence into the interior `of the clutch housing 26 through the said ports 21.

When the compressor is started, the blades or varies 24 of the driving element 22 will act upon the oil in the housing 26 and when the centrifugal force upon the oil developed'by said drivingiimpeller structure 22 reaches a degree suiiicient to overcome the tension of the spring I6 as exerted against the cam I through the medium of the head Il, a coupled condition will exist between the f driving element 22 and the driven element 20 of the hydraulic clutch structure 2|, and since the driven element 20 is connectedto the camIS, the cam will be rotated in a counterclockwise direction. The head Il ofthe valve stem .I I, riding upon the surface of thefcam I5, will cause an outward or upward movement of the valve stem II and the valve 9, moving the valve` 9 into position upon its seat Il and closing the ports ,8, cutting off communicationbetween the pipe 5 and atmosphere. Thus, during-the continued operation of the compressor, it will be in -a loaded condition.

The cam I5 has a stop 30 formed' onits periphery, and when the cam has moved a sufliclent distance to seat thevvalve 9, further rotation ofthe cam will be arrested through engagement of -the head Il of the stem II against said stop". At such time the hydraulic clutch will in effect slip and continued seating and unseating ofthe'valve S, such as would be occasioned if the cam I5 were allowed to continue rotating duringoperation of the compressor, will be prevented,fbutithe centrifugal force exertedagainst the vanes25 `oiflthe driven element 2B through the medium-of the oil 'being acted uponzby `the driving element 22w'il1 be suillcient to maintain the. cam .I5 inits valve seating position.

When the compressor is stopped, the coupled relation between the driving element 22 andthe driven element 20 of the hydraulic clutch stru `3| in the structure shown in the drawings, it is vto be understood that any other suitable means such as to warrant. the hydraulic coupling and ture 2| will of coursebe broken and the cam 'I5 will be moved in a clockwise direction through the medium of the counterweight 3| attached thereto, and the head I4 of the stem II, following the peripheral surface of the cam -I5, `'willpermit the valve 9 to be moved downwardly, under action of the spring I6, to open the ports `8 to atmosphere and thus unload the compressor. of the cam I5 in suchclockwisedirection' into valve unseating position is limited by means of the stop 32 formed on the periphery of the cam.

By varying the tension of the spring IIthe'time delay before loading of the compressor, upon ating speed required before loading of the compressormay be varied, since by adjustment ofthe `tensionn'ii the spring I6 variation of `the power, developed through the hydraulic clutchI structure 12| `as driven by the shaft 3, required to move ther-cam I5 into position for loading the compressor is provided. In other words, byincreasing -the tension of the head Il againstrthe` surface of the cam I5, Y a higher speed of theshaft '3 is `required fordeveloping the power required fory moving or-rotating said cam.

While the cam I5 is returned to compressor un` loading position by means of the counterweight y The movement v its companion mechanism may be mounted or `otherwise suitably connected to the driving shaft ofthe prime mover.

It will be understood that the invention is not to be `limited to the speciiic construction or arwn, but that they may be the invention defined by rangement of parts sho widely modified within the claims.

What is claimed is:

l. In an unloader for compressors, the com-` bination of a compressor including a compression space, an operating shaft for the compressor, and a lubricating system, a valve housing having a. passage open to said compression space and to atmosphere to permit unloading of the compressor, a valve in said housing seated to close said passage Vto atmosphere to load the compressor and unseated when the compressor is not operating to unload the compressor, a cam for seating said valve and-holding it in seated position, a hydraulic coupling comprising driving and driven parts connectingsaid cam and operating shaft wherebyvwhen the operating shaft reaches suilicient Speed 'of rotation to set up coupled connection of said driving and driven parts of the hydraulic coupling the valve will be seated to load the compressor, means connecting said hydraulic coupling to said lubricating system whereby the hydraulic coupling will receive operating oil from the lubricating system, and tensioned means cooperating with the cam for applying tension to the cam to control the operation of the cam by said hydraulic coupling, i

A2. In an unloader for compressors, the combination of a compressor including a compression space, an operating shaft for the compressor, and alubricating system, a valve housinghaving a passage open to said compression `space and to atmosphere to permit unloading of the compressor, a valve in said housing vseated to close said passage to atmosphere to load the compressorand unseated when the compressor is not operating to unload the compressor, a cam for seating said valveand holding it in seated position, a' hydraulic coupling comprising driving and driven parts connecting said cam and operating shaft whereby when the operating shaftreaches sufficient -speedof rotation to set up coupled connection of said driving and driven part-sv ofthe hydraulic coupling the valve will be seated to load the compressor, means connecting-said hydraulic coupling to said lubricating system'whereby' the hydraulic coupling will receive operating fluid from the lubricating system, tensionedmeansco'- operating with the cam for applying tensionlfto the cam to control the operation of the'cam'by said hydraulic coupling, and adjustable means for regulating the Y tension of said Ytensioning means for regulating the pressure developed by -said hydraulic coupling required for-operating said cam. "-f

3. `In an unloader vfor compressorsfth'e com- 'binaton with a compressor including an operatof pressure required for rotating the cam to seat ing shaft and a compression space, and a lubricating system, of a valve housing having a passage open to said compression space and to atmosphere to permit unloading of the compressor, a valve in said housing seated to close said passage to atmosphere to load the compressor and unseated when the compressor is not operating to unload the compressor, a cam for seating said valve and holding it in seated position, a hydraulic coupling comprising driving and driven parts connecting saidv cam and operating shaft whereby when the operating shaft reaches sufcient speed of rotation to set up coupled connection of said driving and driven parts of the hydraulic coupling the valve will be seated to load the compressor, means connecting said hydraulic coupling to said lubricating system whereby the hydraulic coupling will receive operating fluid from the lubricating system, tensioned means cooperating with the cam for applying tension to the cam to control the operation of the cam by said hydraulic coupling, adjustable means for regulating the tension of said tensioning means for regulating the pressure developed by said hydraulic coupling required for operating said cam, means associated with said cam for operating the cam to permit unseating of the valve upon breaking of the coupled connection between the driving and driven parts of the coupling, a stop on said cam for arresting movement of the cam when the valve is fully seated and a second stop on said cam for arresting movement of the c'am when the valve is in fully unseated position.

4. In an unloader for compressors, the combination with a compressor including an operating shaft and a compression space, and a lubricating system, of a valve housing having a passage open to said compression space and to atmosphereto permit unloading of the compressor, a valve in said housing seated to close said passage to atmosphere to load the compressor and unseated when the compressor is not operating to unload the compressor, a cam for seating said valve and holding it in seated position, a hydraullc coupling comprising driving and driven parts connecting said cam and operating shaft whereby when the operating shaft reaches sufiiclent speed of rotation to set up coupled connection oi said driving and driven parts of the hydraulic coupling the valve will be seated to load the compressor, means connecting said hydraulic coupling to said lubricating system whereby the hydraulic coupling will receive operating iiuid from the lubricating system, a spring for applying pressure to said cam to regulate the degree said valve, and adjustable means for regulating the tension of said spring to provide regulation of the degree of pressure required to rotate the cam into valve seating position.

5. In an unloader for compressors, the combination with a compressor including an operating shaft, a compression space and a lubricating system, of a valve structure open to said cornpression space and constructed and arranged to load the compressor when seated and unload the compressor when unseated, means for operating said valve structure, a housing connected to said compressor and being open to the lubricating system of the compressor for receiving oil therein, a hydraulic coupling in said housing connected to and operated by said operating shaft, said hydraulic coupling being provided with openings to receive therein oil from said housing, and means connecting said hydraulic coupling to said valve structure operating means.

6. In an unloader for compressors, the combination with a compressor including a compression space, an operating shaft and a lubricating system, of a valve structure having communication withsaid compression space to unload the compressor when the valve is open and load the compressor when the valve is closed, a hydraulic coup 'ng comprising driving and driven parts, said driving parts connected to said operating shaft for operation thereby, means connected to said driven part and operated thereby for operating said valve, a housing about said hydraulic coupling and provided with means for receiving oil from the lubricating system of the compressor, said hydraulic coupling provided with ports to permit ingress of oil thereinto from said housing, and means for applying tension to said driven member.

7. In an unloader for compressors, the combination with a compressor including an operating shaft, a compression space, and a lubricating system, of a valve structure open to said compression space and constructed and arranged vto load the compressor when seated and unload the compressor when unseated, means for operating structure, a hydraulic coupling connected to and operated by said operating shaft, hydraulic coupling and hydraulic coupling to said valve structure operating means.

PAUL DISEREN S. 

